ES2370755T3 - THERMOENDURECIBLE POLYESTER ACRYLIC RESIN COMPOSITION FOR GEL COATING WITH LOW CONTENT IN VOC. - Google Patents

Abstract

Low VOC thermosetting polyester acrylic resins are made by esterification of unsaturated epoxide such as glycidyl methacrylate, and a polyacid which is the half-ester formed by reacting an acid or its anhydride with a polyol is disclosed. The obtained low viscosity resin is useful for making a low or zero VOC gel coat with excellent hydrolytic and weather resistance.

Description

Thermosetting polyester acrylic resin composition for gel coating with low VOC content

The present invention is in the field of thermosetting resin compositions for gel coatings

or molded composite material, more preferably gel coating compositions and related components, process for making said resin compositions, in particular for use in the realization of gel coated articles, process for making gel coated articles and final articles, in particular coated articles with gel

Conventional gel coating compositions, typically formulated from thermosetting resins such as unsaturated polyester, acrylate and urethane resins and combinations thereof are useful in the form of the outer paint layer for composite materials such as boat hulls, bath compartments , and the like. A gel coating is a pigmented, charged and pre-promoted resin (usually unsaturated polyester) that is sprayed with a mold starter from a high pressure spray gun at a film thickness of up to 0.75 mm. The film cures glass and laminated resins before reinforcement. The gel coating should have low viscosity at high shear, should resist molding, and produce a gel time of 8-15 minutes. For marine applications, gel coatings should have hydrolytic stability and good weather resistance.

Unsaturated polyester resins are generally prepared by reacting them in a glycol with an unsaturated acid and then mixed with reactive diluents such as styrene and methyl methacrylate (MMA). Reactive diluents are also used to reduce the viscosity of the resin system. When cured, reactive diluents form part of the resin system to produce a rigid crosslinked structure with desirable properties. Conventional unsaturated polyester resin usually contains 45% to 35% by weight of reactive diluents and other volatile organic compounds (VOCs).

The presence of large amounts of styrene and other VOCs in such resin compositions results in the emission of styrene vapors into the work atmosphere, which constitutes a danger to workers and the environment. In view of this danger to the environment, governments have established regulations that set out guidelines regarding volatile organic compounds that can be released into the atmosphere. The U.S. Environmental Protection Agency (EPA) It has established guidelines that limit the amount of VOCs released into the atmosphere, such guidelines being provided for adoption or adoption by several states in the United States. The guidelines that refer to VOCs, such as those of the EPA, and environmental issues pertain particularly to gel coating and other sectors of the coating using styrene or organic solvents and these VOCs are emitted into the atmosphere.

To reduce the content of styrene and VOC in polymeric vehicles and formulated coating, researchers are trying to develop resin compositions with a low VOC content in which VOCs are kept at the lowest possible level in the coating. One way to reduce VOCs is to reduce the molecular weight of laresin. According to the physical theory of the polymers, the viscosity of the polymers in the liquid state depends mainly on the average molecular weight, so it is convenient to reduce the average molecular weight for the product with low VOC. The low molecular weight leads to a lower viscosity and a need for lower styrene. In comparison to the conventional resin, which has a higher molecular weight and a higher styrene content, the resin with low VOC normally contains 35% or less of styrene and VOC.

The resin with lower molecular weight has the advantage of reduced VOC, but also has disadvantages with respect to the conventional resin. Gel coating or coating made with lower molecular weight resin tends to have poor properties in application compared to conventional resin. While conventional resin tends to form a cure surface without adhesion, the surface of the gel or composite coating, more particularly of the coating or gel coating made with lower molecular weight resin, tends to remain adhered for long periods of time after application. The adhesion of the surface is due to the inhibition of oxygen in radical polymerization.

To achieve a surface or coating without adhesion, for example, a film-forming material, such as paraffin wax, can be included in the coating composition in order to prevent air inhibition and reduce monomer vaporization. Paraffin or hydrocarbon waxes tend to migrate to the surface, particularly the coating, and act as a film that reduces the penetration of oxygen into the coating surface. However, the presence of wax on the coating surface will reduce secondary adhesion properties when the laminate is placed on the coating later.

Performance and low VOC are incompatible characteristics between them. Improved poor performance and obtaining non-adhesion tend to damage the property of low VOC. There is a difficulty to achieve both low VOC properties and good application.

It is convenient, particularly in view of the toxicity of the styrene monomer and government regulations, to reduce the concentration levels of the styrene monomer from 40% to 50% in normal weight of the depolyester resin to below 35% or 30% in weigh. However, reductions in concentrations of styrene monomers present problems in polyester resins. The viscosity of the resin increases with a lower monomer content causing difficulties in the application of the resins, such as poor spray property and glass stretching when the resin is sprayed or used in combination with glass fibers. In addition, the physical properties of polyester resins with reduced styrene monomers are also greatly reduced without the use of additional, complementary crosslinkers in the polyester resin. Monomosacrylics, such as ethylene glycol dimethacrylate have been added to polyester resins with low or reduced styrene monomers for marine grade gel coatings and for outdoor applications. However, the resulting resin is difficult to use due to its adherent surface.

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In addition, in unsaturated polyester resin, an aromatic diacid, such as isophthalic acid, is generally present to help improve the hydrolysis resistance of the film. However, the presence of nucleosaromatics produces poor exterior durability to the coating film. The same problem also occurs in vinyl ester resins. Low VOC vinyl esters based on polyepoxide-aromatic resin reacted with unsaturated monocarboxylic acid and other moieties are described in US Pat.

6,900,276. Although the styrene content is lower, the presence of the aromatic nuclei leads to unacceptable exterior durability. Vinyl esters based on aliphatic polyepoxides show poor hydrolysis resistance. Both vinyl ester resins are not suitable for gel coatings that require good hydrolytic stability and weather resistance.

Therefore, it is desirable to provide new and better crosslinkable resin compositions to provide unsaturated resins with better physical and chemical properties and to provide an unsaturated resin composition having reduced styrene monomer at the same time. In the prior art, several approaches have been described to address these limitations. These approaches include embodiments of the polyesterol modifications using epoxy chemistry, urethane chemistry and acrylic chemistry.

Acrylic resin without aromatic cores shows good properties and is developed for many applications, including gel coating. Some acrylic based resins have been reviewed for the formulation of the gel coating. Unsaturated modified acrylic resins are taught in EP 708 157, US patents. 4,742,121 and 6,492,470 teach acrylic resins for gel coating comprising a vinyl monomer and a polyacrylate with various unsaturated pendant groups.

Acrylic resins with urethanes have been reviewed through various techniques. U.S. Pat.

5,777,053 and 7,150,915, JP 59157074, EP 0 254 232 and WO 2004/014978 teach acrylic polymers containing urethane groups and are crosslinkable by vinyl polymerization. The urethane groups are introduced by reacting the pending hydroxyl group of the central acrylate or polyester structure with polyisocyanate.

WO 2004/056930 described UV curable epoxy acrylates. JP 60123478 described the acrylate resin containing the isocyanuric ring. The thermosetting acrylic resins were also synthesized with the reaction of the polyacid and unsaturated epoxide, such as glycidyl methacrylate. U.S. Pat. 4,774,267 and

4,831,066 reviewed the polyol ester medium and the acid anhydride was esterified with glycidyl methacrylate to obtain a photocurable dental material. JP 63113011 and JP 2001011153 described an ink coating or UV curing composition made by means of the reaction of half a half glycerol ester and anhydrous acid with glycidyl methacrylate.

US 6,617,417 discloses ambient temperature curable unsaturated polyester resin compositions and comprising divinyl ethers, whose compositions are suitable for gel coatings, laminating resins and applications that require a thicker layer of product. These polyesters can be modified acrylate or methacrylate as exemplified in Example 1, where the Pm is 1500, the ICI viscosity of 6 P, for a modified polyester resulting from a polyester polyacid based on an aromatic acid component and an epoxy methacrylate.

EP 384 729 refers to radiation curable acrylated polyester compositions, said polyresters resulting from the reaction of a diol with a polybasic acid and a glycidyl acrylate. These compositions can be used in the form of coatings, inks and adhesives, with high cure rates. The functionality of said acrylated polyesters is from 2 to 6.

EP 1 149 874 discloses polymerizable unsaturated polyester resin compositions comprising an unsaturated polyester resin having extreme methacryloyl groups and an ethylenically unsaturated comonomer, wherein said methacrylated polyester is the reaction product of a terephthalate oligomer diol, emitted by PET alcoholysis (PET residue), with a dibasic acid containing a dibasic aromatic acid and a glycidyl methacrylate.

US 3,899,611 discloses radiation curable coating compositions comprising prepolymers terminated in acrylic with Pm from 170 to 30,000 and alkyl acrylate ether of melamine, with more than 3 acrylate per triazine ring.

While these approaches have led to improvements in hydrolytic stability and durability, none of these solutions to the problems caused by low viscosity and poor application properties have been completely unsatisfactory. There is still a significant need for thermosetting resin that has a better decuration product, especially in the case of low VOC resins, which contain relatively low convolatility vinyl monomers, and with outstanding weather resistance.

It is an object of the present invention to provide a new crosslinkable resin composition that avoids high VOC problems and provides a gel coating that can be used in a wide variety of applications. It is a further object of the present invention to provide a crosslinkable polyester acrylic resin composition that can be formulated to a gel coating composition with high solids content with excellent weather, gloss and water resistance that allow the degel coating composition to be use in the form of gel coatings with a low VOC content or in a mold coating system, in particular for use in the form of a gel coating for ships and automobiles.

The above deficiencies of gel coatings have been largely overcome with degel coatings based on the acrylic acrylic resins of the present invention. The new polyester acrylic gel coatings show excellent viscosity and excellent hydrolytic and temperature stability.

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In accordance with the present invention, a first subject of the invention relates to a crosslinkable resin composition comprising a polyester acrylic resin that is the reaction product of a polyacid, which is a half-ester formed from the reaction of a acid or its anhydride with a polyol, and an unsaturated epoxide, said resin composition also containing at least one polymerizable vinyl monomer. A thermosetting resin blend composition, comprising at least one resin composition of the invention and at least one different thermosetting resin, is also part of the invention. Said resin composition and said thermosetting composition that are suitable for gel coatings is another object of the invention.

Another subject of the invention relates to a process for carrying out said crosslinkable resin composition of the invention which comprises, firstly, the preparation of a reaction medium-ester of a polycarboxylic acid or of the corresponding anhydride and polyol and then the esterification of the medium. - resulting ester with unsaturated epoxide.

A gel coating composition or a molding composition, preferably a gel coating composition, which may be non-pigmented, but is preferably pigmented with at least one pigment, said composition comprising at least one of the crosslinkable resin compositions of the invention , also part of the present invention.

Other subjects of the invention relate to the use of a resin composition according to the invention to make pigmented or non-pigmented gel coatings or mold coatings, preferably for marine, sanitary or automotive applications or for the realization of molded composite materials, preferably for reinforced composite products. A more particular use is to make gel coatings for coating a molded composite substrate that can be made from both said resin composition and from said composition of the thermosetting mixture, as defined above, or from unsaturated polyester resin (UPR) or from devinyl ester resin or any other thermosetting resin composition. The final articles, such as degel coatings or molded composite materials as a result of a gel coating or a molding composition and their uses in accordance with the present invention, or the articles comprising said gel coating or said molded composite material also form part of the present invention.

The acrylic polyester polymer (or resin) contains less than 10% by weight of aromatic component (aromatic ring structure), and can be adjusted without the formation of high molecular weight materials, which allows the formulation of crosslinkable compositions with high content in solids, more particularly gel compositions with high solids content that provide cured coatings with excellent properties. The term " acrylic " It must be understood in the sense of resin "acrylic or functional acrylate". The half-ester synthesis procedure is not only good for the preparation of a desired molecular structure, but it is also convenient to introduce functional groups into the main structure of the polymer (saturated main structure). The polyester or resin acrylic polymer contains acrylate unsaturated ester linkages (acrylic ester groups) and preferably also contains free secondary hydroxyl groups (OH). Said free secondary hydroxyl groups (OH) can be used for further modification of the resin, for example, by reacting with at least one functional prepolymer of diisocyanate, polyisocyanate or isocyanate or polycarboxylic acid anhydride.

Crosslinkable resin compositions can be used to make gel coatings and mold coatings with less monomer.

The crosslinkable resin compositions of the invention comprise a polyester acrylic polymer having at least two (two or more) polymerizable carbon-carbon double bonds, which are acrylate groups, in each molecule (molecular chain) and at least one polymerizable vinyl monomer (co-polymerizable), the acrylic reaction dichopolymer being the reaction product of:

(one)

 A polyacid; Y

(2)

 An unsaturated epoxy, which contains a carbon-carbon double bond and with an average molecular weight in the number of 560-200 and a viscosity of less than 1500 mPas (1500 cp) in a solution with 30% styrene demonomer and said polyacid being a half ester and the reaction product of a polyol or a mixture of polyols with one or more polycarboxylic acids or carboxylic acid anhydrides with said polyol or mixture of depoliols with an average of at least two hydroxyl groups in the molecule and with an average hydroxyl number of 56 to 1830 and with an average molecular weight in number of polyol or mixture of polyols between 72 and 2000. Preferably, the polyol or mixture of polyols has an average hydroxyl number of 130 to 1500, and an average molecular weight in number between 110 and 1800.

Preferably, the molar ratio of the hydroxy groups to the acid groups in the reaction to perform polyamides, is at least 0.4: 1.6 (1/4) and the ratio of the remaining equivalents of the carboxy groups of the medium -Ester to the equivalents of the reaction of epoxy groups, the unsaturated epoxide, is preferably 0.5 to 2 and more preferably about 1: 1 more particularly 0.8 to 1.2.

The resulting crosslinkable resin composition has a viscosity of less than about 1,500 mPa.s

(1,500 cp) for a 70% styrene resin solution of nonvolatile matter (solids or resin content), which is a resin solution (styrene) with 30% by weight styrene monomer, having the acrylic polymer depolyester an average molecular weight in number from 560 to 2500.

A further aspect of the invention relates to a gel coating derived from polyester acrylic resin compositions and articles of manufacture of, in particular, ships and sanitary facilities formed with the resin compositions described above and having hydrolysis and resistance to the improved weather.

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The first step in the manufacture of the resin of this invention is to make a polyacid or ester medium by means of the reaction of a polyol or a mixture of polyols with the polycarboxylic acid or its anhydride.

The second step in the manufacture of the resin of this invention is to make a polymer from the above-defined polyacid by reacting said polyacid with said unsaturated epoxide, which may include at least one such as glycidyl methacrylate, glycidyl acrylate or allyl glycidyl ether. The resulting polymer has a number average molecular weight in the range of about 560 to about 2500, preferably about 800 to about 2000. If the molecular weight is less than about 560, the gel coating and curing properties will be poor. If the molecular weight is greater than about 2500, the resulting resin will have a high viscosity and cannot be used to make gel coatings with a low VOC content.

Finally, at least one polymerizable vinyl (co) monomer is added until the solution reaches a certain viscosity, which is less than about 1,500 mPa.s (1,500 cP), preferably less than about 1,000 mPa.s (1,000 cp), measured with Brookfield viscometer at 25 ° C in a 70% solution of styrene resin (polymer) of non-volatile matter (solids or resin content), which is a 30% by weight resin solution (enestirene) of monomer of styrene.

The resulting polymer is diluted with suitable vinyl monomers selected from various groups of monomers, such as monofunctional and multifunctional methacrylates and acrylates (in the form of additional crosslinking agents in case of multifunctional monomers), as well as other monomers, oligomers and polymers capable of participating. in polymerizations with the addition of free radicals such as styrene, toluene vinyl, alpha methyl styrene, acrylic monomers, etc.

Among the polyols that can be used to make such polyacids or half esters are simple polyols, that is, those containing from about 2 to about 20 carbon atoms, as well as polymer polyols such as polyester polyols, which include polycaprolactone polyols, polyols of polyurethane, polyether polyols, polycarbonate polyols and polyester carbonate and acrylic polyols. Polyol compounds

or polyhydroxyl acids have an average of at least two hydroxyl groups in the molecule, a hydroxyl number of about 56 to about 1830, preferably 130 to 1500, and an average molecular weight in number between 72 and 2,000, preferably between 92 and 2000, more preferably between 110 and 1800. Examples of polyol or polyhydroxy compounds include hexanediols, ethylene glycol, di–, tri– and tetraethylene glycol, propylene glycol, di–, tri– and tetrapropylene glycol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 2,2,4– Trimethyl-1,3-pentanediol, 1,4-bis (hydroxymethyl) -cyclohexane, 2,2-bis (4-hydroxycyclohexyl) propane, trimethylolpropane, glycerol, hexanotriol, N, N ', N " - tris– (2– hydroxyethyl) -isocyanurate (THEIC) and pentaerythritol.

Examples of relatively high molecular weight polyhydroxyl compounds include the known polyester polyols obtained by the reaction of dicarboxylic acids or their anhydride such as hexahydrophthalic anhydride, nadic anhydride, tetrahydrophthalic anhydride, maleic anhydride with polyols such as those mentioned above. These polyester polyols include both saturated and unsaturated polyester polyols. The unsaturated polyester polyol has at least one ethylenically unsaturated group per molecule and predominantly hydroxy terminal groups. The unsaturated polyester polyol, for example, is an oligomer of an alpha, beta-ethylenically unsaturated dicarboxylic compound, obtained by means of the condensation reaction of one or more unsaturated di-or polycarboxylic acids or anhydrides and / or one or more acids or anhydrides di-o polycarboxylic saturated with an excess of glycols or polyhydric alcohols under the conditions known in Latin America.

The mixtures of the aforementioned starting materials can, of course, be used to carry out the process according to the invention. Other suitable polyol compounds include compounds derived from the polyol / caprolactone adduct.

Preferred polyols are polyhydric alcohols with three or four hydroxyl groups, especially polycaprolactone triol (also known as polyol Tone) having a hydroxyl number of about 130 to about 1200 and a number average molecular weight between about 190 and about 1800. Tone polyols can be obtained from the reaction of a lactone such as epsilon-caprolactone and unpolyol, such as ethylene glycol, diethylene glycol and trimethylolpropane (TMP). The Tone polyol can be prepared in a separate previous reaction or in situ in the same reaction vessel, as the esterification reaction. The preparation of Tone-polyol is known in the art and is described, for example, in JP 60123478.

The oligomeric aliphatic polyester diol can also be synthesized by reacting an aliphatic lactone, such as caprolactone, with an aliphatic diol. In one embodiment, the oligomeric aliphatic polyester diol has a number average pesomolecular of about 180 to about 2000. Preferably, the average number of polyol pesomolecular is in the range of about 190 to about 1800. The techniques suitable for preparation Oligomeric polyester diols include those known in Latin America for the preparation of polyesters. Suitable oligomeric aliphatic polyester diols are commercially available such as, for example, Desmophen® S1015-120 from Bayer (formerly marketed as RUCOFLEX S1015-120), and Tone ™ 301 from Dow.

In one embodiment, the polyol compound comprises an oligomeric aliphatic polycarbonate diol. An oligomeric aliphatic depolycarbonate diol is a reaction product of a diol and a carbonate precursor. The carbonate precursor may include phosgene, haloformate, or a carbonate ester. Suitable diols are the same as those described above for oligomeric aliphatic polyester diol. In one embodiment, the oligomeric polycarbonate aliphatic diol has a number average molecular weight of about 200 to about 2,000. Suitable techniques for the preparation of oligomeric polycarbonate diols include those known in the art for the preparation of polycarbonates, in general.

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In one embodiment, the polyol compound comprises an oligomeric aliphatic polyester carbonate diol. Such compounds are essentially hybrids of oligomeric aliphatic polyester diols and oligomeric polycarbonate aliphatic diols described above, in that they contain two terminal hydroxy groups and internal carbonate bonds and ester bonds. In one embodiment, the oligomeric aliphatic polyester carbonate diol has a number average molecular weight of at least about 200. Oligomeric aliphatic polyester carbonate diols can be prepared from a diol, a diacid and a carbonate precursor, using techniques known in the art for Polyester carbonate preparation. Suitable aliphatic oligomeric polyester carbonate diols are available, such as, for example, Desmophen® VP LS 2391 (formerly marketed as Bayer's Desmophen® C200).

In addition to polyester polyols, polyurethane polyols such as urethane-polyester polyols can be used which are formed by reacting an organic polyisocyanate with a polyester polyol, such as those described above. The organic polyisocyanate is reacted with a polyol such that the equivalent OH / NCO ratio is greater than 1: 1 such that the resulting product contains free hydroxyl groups. The organic polyisocyanate that is used in the preparation of polyurethane polyols can be an aromatic or aromatic polyisocyanate or a mixture. Diisocyanates are preferred, although higher polyisocyanates, such as triisocyanates, may be used, but result in higher viscosities.

The oligomeric aliphatic polyurethane diol can also be prepared according to the procedures known in the art for the preparation of polyurethanes. Suitable oligomeric aliphatic polyurethane diols are commercially available, such as King Industries K-FLEX ® UD-320. These urethane diols are the reaction products of carbonates and amines.

In one embodiment, the polyol compound comprises any of the diol compounds described above in combination with a triol compound. Suitable triol compounds include, for example, trifunctional polycaprolactonasoligomeric, available as Tone ™ 301, Tone ™ 305 and Tone 310 ™ from Dow, and polyesteraliphatic triol available as Desmophen ® F2037-420 from Bayer. The weight ratio of the diol compound to compuestotriol can be about 1: 99 to about 99: 1, specifically about 20:80 to about 80:20.

The hydroxyl groups in the aforementioned polyol may be at least partially silylated. By means of lasilylation of hydroxyl groups, the viscosity of the coating material can be further reduced. By means of the silylation of not less than about 20 mol%, preferably not less than about 50 mol% of the existing hydroxyl groups, the effect of viscosity reduction can be increased traditionally.

The ester medium (or polyacid) is obtained by means of the reaction between polyols and polycarboxylic acids and / or their anhydrides under conditions of excess acid to a hydroxyl functional group. The equivalent ratio of acid to hydroxyl in the polyol is preferably at least 1.35: 1 to obtain the maximum conversion to the desired polyacid. Ratios of less than 1.35: 1 may be used but such ratios result in increased formation of less preferred polyacids. Such reaction products are of relatively low molecular weight, with narrow molecular weight distributions, and provide low content of volatile organic compounds in the coating composition, still providing excellent properties of the resulting coating.

Among the anhydrides that can be used in the formation of the desired polyacids are those that, without including the carbon atoms of the anhydride moiety, contain from 2 to about 20 carbon atoms. Suitable polycarboxylic acids include, but are not limited to, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, cyclohexane dicarboxylic acid, sebacic acid, azelaic acid, malonic acid, succinic alkenyl acid such as n-dodecenyl succinic acid, dodecylsuccinic acid, octadecenyl succinic acid. Lower alkyl esters of any of the above may also be used.

Examples of aliphatic polycarboxylic acid anhydrides include cycloaliphatic, olefinic and cycloolefinic anhydrides. Substituted aliphatic anhydrides are also included within the definition of aliphatic as long as the substituents do not adversely affect the reactivity of the anhydride or the properties of the resulting polyester. Examples of substituents would be chlorine, alkyl and alkoxy. Examples of anhydrides include anhídridosuccínico, metlsuccínico anhydride, dodecenyl succinic anhydride, octadecenyl succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyl-tetrahydrophthalic, hexahydrophthalic anhydride, alkylhexahydrophthalic anhydrides such as methylhexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, chlorendic anhydride, itaconic anhydride, citraconic anhydride, nadic anhydride and anhydride.

The resulting polyacids are relatively low in molecular weight and quite reactive with epoxies that allow the formulation of fluid compositions with high solids content, while maintaining prominent properties such as adhesion, gloss and water resistance.

The resulting polyacid is then reacted with said unsaturated epoxide, which is more particularly an ethylenically unsaturated monomer containing epoxy groups, in addition to ethylenic unsaturation. Preferred examples of ethylenically unsaturated monomers containing epoxy groups are those containing 1,2-epoxy groups and include glycidyl acrylate, glycidyl methacrylate (GMA) and allyl glycidyl ether.

An esterification catalyst is not necessary; however, the use of a catalyst as such is highly desired. In general, any esterification catalyst is suitable for use in the preparation of vinyl esters including metal hydroxides such as sodium hydroxide; tin salts such as tin octoate; phosphines such as triphenylphosphine, onium salts, such as phosphonium salts, including phosphonium and ammonium halides.

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Preferred esterification catalysts comprise onium salts, and preferably those containing phosphorus, sulfur or nitrogen, such as, for example, phosphonium, sulfonium and ammonium salts of inorganic acids. Examples thereof include, but are not limited to, sulfate. of benzyltrimethylammonium chloride, tetramethylammonium chloride, oxymethyltrimethyl ammonium chloride, tetramethylammonium chloride, benzyltrimethylammonium nitrate, diphenyldimethylammonium chloride, benzyltrimethylammonium chloride, diphenyl dimethyl ammonium nitrate, diphenylmethylsulfonphthylphosphonium, diphenylphosphonium diphenylphosphonium phosphonate trimethylsulphonium, dedicyclohexyldialkylphosphonium iodide, benzyltrimethylammonium thiocyanate, and the like, and mixtures thereof.

The amount of the aforementioned unsaturated epoxide and the acid to be used in the reaction can vary over a wide range. In general, these reagents are used in approximately chemical equivalent amounts. As used herein and in the appended claims, a chemical equivalent amount of GMA refers to the amount needed to provide an epoxy group per carboxy group. Excessive amounts of any reagent can be used. Preferred amounts vary from about 0.5 to about 2 equivalents of carboxylic acid per epoxy equivalent.

The amount of catalyst employed can also vary in a considerable range. In general, the amount of the catalyst ranges from about 0.01% to about 3% by weight, and more preferably from about 0.3% to about 2% by weight of the reagents.

The reaction can be carried out in the presence or absence of solvents or diluents. In most cases, the reagents will be liquid and the reaction can be carried out easily without the addition of odilucent solvents. However, in some cases, if one or both reagents are solid or viscous liquids, it may be desirable to add diluents to help effect the reaction. Examples of such materials include inert liquids, such as inert hydrocarbons such as xylene, toluene, cyclohexane and the like.

If the solvents are used in the reaction and the resulting product is to be used for coating purposes, the solvent can be retained in the reaction mixture. Otherwise, the solvent can be removed by any suitable procedure, such as by distillation and the like. If the product is to be stored for a long time after its formation, it may also be convenient to remove the catalyst used in the preparation, such as by purification, neutralization and the like.

The temperatures used in the reaction generally vary between approximately 50 ° C and approximately 150 ° C. In most cases, the reagents will be combined in the presence of the new catalyst at a very fast speed and the lower temperatures will be satisfactory. Particularly preferred temperatures would range from about 60 ° C to about 120 ° C.

The reaction is preferably carried out at atmospheric pressure, but it may be advantageous in some cases to use subatmospheric or superatmospheric pressures.

The development of the reaction can be conveniently monitored through the acidity determination. The reaction is considered to be substantially complete when the acidity has been reduced to approximately 0.015 eq / 100 grams or below.

The process of the invention may be affected in any suitable manner. The preferred process merely comprises the addition of GMA and polyacid, catalyst and solvent or diluent, if desired, in any order and then applying the heat necessary to carry out the reaction. The reaction mixture can then be distilled or purified to remove any of the unnecessary components, such as solvents, catalyst, excess reagents and the like.

The polyester products obtained by the above procedure will vary from liquids to solid resins. The products have a plurality of free OH groups and a plurality of ethylenic groups. The products will be of greater molecular weight than the basic polyacid from which they are formed and possess at least more than one ester group per polyacid unit.

These polyester acrylic resins can then be modified, if desired, by further reaction with an isocyanate or polycarboxylic acid anhydride such as maleic anhydride.

The resulting polyester acrylic resin is mixed or combined with one or more compatible unsaturated monomers, examples of such monomers include, among others, aromatic compounds such as styrene, alpha-methylstyrene, dichlorostyrene, vinyl naphthalene, vinyl phenol and the like, unsaturated esters, such as acrylic and methacrylic esters, vinyl laurate, and the like, unsaturated acids, such as acrylic and alpha-alkylacrylic acids, butenoic acid, allylbenzoic acid, vinylbenzoic acid, and the like, halides, such as devinyl chloride, vinylidene, nitriles, such as acrylonitrile, methacrylonitrile, diolefins, such as butadiene, isoprene, methylpentadiene, esters of polycarboxylic acids, such as diallyl phthalate, divinyl succinate, diallyl maleate, divinyl adipate, tetrahydrophthalate mixtures, and the like, dichlorolate and mixtures same.

The amount of said vinyl monomer can vary widely; however, the weight ratio of the polyester acrylic polymer to the unsaturated monomer will generally vary from about 99.0: 1.0 to about 30.0: 70.0, with preference from about 90.0: 10.0 to about 40.0 : 60.0, and especially preferred from about 80.0: 20.0 to about 50.0: 50.0.

Especially preferred unsaturated comonomers are unsaturated aromatic compounds such as styrene, vinyl toluene and divinylbenzene. Because styrene or other polymerizable, vaporizable, ethylenically unsaturated monomer is a volatile component that tends to be released into the atmosphere during storage and / or curing of thermosetting polyester and unsaturated polyester resins, it is increasingly desirable to reduce the level of styrene or other polymerizable, vaporizable monomer that is released at

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atmosphere during storage and / or healing. If the acrylic oligomer, such as SR 239, SR306 from Sartomer, is used as a monomer, it is possible to obtain a gel coating with zero VOC.

Stabilizers are used to stabilize resins during storage. Suitable stabilizers include sulfide phenols and sterically hindered amines. Examples of especially preferred stabilizers include, among others, 2,6-di-tert-butyl-4-methylphenol, 1,3,5-trimethyl-2,4,6-tri (3 ', 5'-di-tert-butyl-4' - hydroxybenzyl) benzene, 3– (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) octadecyl propionate, bis (2,6-di-tert-butylphenol) 4,4'-methylene, dibutyl zinc dithiocarbamate. Exceptional color stability is achieved with these sterically hindered phenols. Hydroquinone is preferably added during the esterification step, but may be added at any time and the stabilizer is preferably added to the finished vinyl ester or the vinyl ester / styrene mixture.

In general, the amount of each stabilizer used in the mixture can vary widely. Consequently, a stabilizing amount that matches the desired final color is used. The amounts generally operable vary from about 2 ppm to about 400 ppm of hydroquinone and from about 2 ppm to about 600 ppm of the stabilizer, based on the weight of the resin. A very effective amount is from about 50 ppm to about 250 ppm of hydroquinone and from about 50 ppm to about 500 ppm of stabilizer. The amount of any additional gelation inhibitor can vary widely and can range from about 100 ppm to about 10,000 ppm.

The resulting stabilized polyester acrylic resins can be converted into very suitable coatings with the addition of a curing agent or use of UV radiation.

Examples of suitable thermosetting resin curing agents (catalysts) are suitable free radical scavenging compounds and UV radiation initiators. Examples of such catalysts include peroxides, such as benzoyl peroxide, tertiary butyl hydroperoxide, butylditerciary peroxide, hydrogen peroxide, potassium persulfate, methyl cyclohexyl peroxide, cumene hydroperoxide, acetyl benzoyl peroxide. Tetraline hydroperoxide, phenylcyclohexane hydroperoxide, tertiary butylisopropylbenzene hydroperoxide, tertiary butylperocetate, tertiary butylacetate, tertiary butyl perbenzoate, diterciate amyl perftalate, diterciate butyl peradipate, percarbonate compounds, such as mixtures of tertiary, percarbonate compounds such as 2,2'-azobisisobutyronitrile, 2,2'-dimethyl azobisisobutyrate, 2,2'-azobis (2,4-diamethylvaleronitrile), 2,2'-azobisisotuliamide, and the like. Particularly preferred catalysts include diaroyl peroxide, tertiary alkyl hydroperoxides, alkyl esters of percarboxylic acids and in particular those of the above-indicated groups, which contain no more than 18 carbon atoms per molecule and have a decomposition temperature below 125 ° C.

Of course, other materials can be mixed or added, including plasticizers, stabilizers, extenders, oils, resins, tar, asphalt, pigments, reinforcing agents, thioxotropic agents, and the like.

The resin compositions present can be used in many applications, such as for coatings and products of molded composite materials or reinforced composite materials, such as laminated products, filament reels, molding sheet compounds (SMC). A very suitable application is for the preparation of the gel coating with good hydrolytic stability and weather resistance. The gel coating composition of the present invention is preferably composed of at least one polymer resin composition, as described above in combination with fillers, pigments, thixotropic agents, and other additives, etc.

Preferred thixotropic agents in the gel coating compositions according to this invention include silica, such as smoked silica and precipitated silica, silica gel, and bentonite clays. The thixotrope is preferably present in an amount of at least about 1% by weight, more preferably at least about 1.5% by weight, up to about 5% by weight, more preferably up to 3.5% by weight, based on the total weight of the gel coating composition.

Examples of fillers include clay, magnesium oxide, magnesium hydroxide, calcium carbonate, calcium silicate, mica, aluminum hydroxide, barium sulfate, talc, etc. The fillers are defined herein without including thixotropes as defined above, as well as dye pigments. Preferred loading amounts are in the range between 5% and 30% by weight.

In a preferred embodiment, the gel coating can be performed by high-speed dispersion of thixotropoy charges in the above resin solution. Then a synergist package is added. A free radical initiator is then added which will facilitate the formation of free radicals necessary for the healing of the gel coating composition. Finally, a vinyl monomer is added to the gel coating composition until the desired viscosity is obtained.

In one embodiment of this invention, the free radical initiator is a photoinitiator, and the gel coating composition is cured by means of UV radiation. These include photoinitiators such as benzophenone, acetophenone and its derivatives, benzoin, benzoin ethers, thioxanthones, halogenated compounds, oximes, and acyl phosphine oxides. Those photoinitiators that discolor considerably when exposed to sunlight are preferred, for example, the oxides of acyl phosphine and 2-hydroxy-2-methyl-1-phenylpropan-1-one.

In another embodiment of the gel coating composition of the invention, a thermally activated curing system is employed, such as a system comprising a metal catalyst and a nonpolyallyl peroxide initiator. In a preferred embodiment of this invention, the thermally activated free radical initiator is an oxidation / reduction system. The oxidation / reduction system comprises a metal catalyst and any combination of one or more compounds selected from the following: amines, alkyl acetoacetates,

60 E08785526 10-28-2011

alkyl acetoacetamides, and alkyl and aryl acetanilides. The gel coating composition can be cured with heat (typically induced by infrared, IR, radiation). The curing temperature is preferably less than 40 ° C, more preferably less than 30 ° C.

The metal catalyst is any metal salt that will promote or accelerate the cure rate of the gel coating composition. Typically, these catalysts are salts of metals and organic acids. Representative metals are cobalt, manganese, vanadium, potassium, zinc and copper. The metal catalyst includes, among others, a variety of metal dryers. Preferred metal salt dryers include cobalt, manganese, vanadium, potassium, zinc and copper octoates, naphthenates and neodeconates. An especially preferred catalyst is a solution of cobalt octoate in an amount preferably in the range of 0.012% to 0.036% by weight of cobalt (for example, 0.1% to 0.3% by weight of a 12% cobalt octoate solution).

The oxidation / reduction system also contains any combination of one or more compounds selected from the following: amines, alkyl acetoacetates, alkyl acetoacetamides and alkyl and aryl acetanilides. For example, dimethylaniline is added in an amount preferably in the range of 0% to 0.4% by weight, more preferably 0.1% to 0.4% by weight. Dimethyl acetoacetate and / or ethyl acetoacetate and / or methyl acetoacetate and / or acetoacetanilide, etc. preferably, in an amount ranging from 0% to 0.2% by weight, more preferably from 0.05% and 0.15% by weight, can be added to the oxidation / reduction system.

In a preferred embodiment of this invention, a peroxide-based co-initiator, more preferably in conjunction with the oxidation / reduction system, is used to cure the gel coating and the lamination resin. These co-initiators are typically non-polyallyl peroxides. They include any of the common peroxides, such as benzoyl peroxide, dialkyl or aralkyl peroxides, such as di-t-butyl peroxide, dedicumyl peroxide, cumylbutyl peroxide, 1,1-di-t-butyl-peroxy-3.5 , 5-trimethylcyclohexane, 2,5-dimethyl-2,5-di-t-butylperoxy hexane and bis (alpha-t-butylperoxy isopropylbenzene); dialkanoyl peroxides such as 2,5-dimethyl-2,5-di (2,5-diethylhexanoyl peroxy) hexane; peroxy esters such as t-butylperoxy pivalate, t-butyl peroctoate, t-butyl perbenzoate, 2,5-dimethylhexyl-2,5-di (perbenzoate), dialkyl butyl carbon carbonates and peroxy dicarbonates; hydroperoxides such as t-butyl hydroperoxide, hydroperoxide of p-methane, pentane hydroperoxide and cumene hydroperoxide, and ketone peroxides, such as cyclohexanone peroxide and methyl ethyl ketone peroxide. Typically, a methyl ethyl ketone peroxide co-initiator (MEKP) is used, which consists of a solution mixture of several peroxides and hydroperoxides, including MEKP monomer, MEKP dimer, MEKP cyclic trimer, and hydrogen peroxide, in a vehicle inert such as dibutyl phthalate.

Other gel coating cure procedures are possible and will be apparent to a subject matter expert. The cured gel coating preferably has a Gardner color of about 2 or less, more preferably about 1 or less, on the Gardner-Holt color scale of 0 to 18 measured in accordance with ASTM D 1544.

The gel coating process is well known in the art. The gel coating composition is applied to the surface of a mold and allowed to partially cure. If the gel coating composition contains a photoinitiator as the free radical initiator, then the gel coating composition is exposed to radiation with the appropriate wavelength and intensity to activate the photoinitiator. If the gel coating composition contains a thermally activated free radical initiator, then the gel coating composition is exposed to heat, preferably in the form of IR radiation. The partially cured gel coating composition is relatively soft, possibly even sticky.

An article that will be gel coated is applied to the partially cured gel coating composition to form a laminate and the laminate is subjected to a second stage cure. This second stage cure can be carried out by heating the mold at an elevated temperature or by other means, such as irradiation. Subsequently, the gel coated article is removed from the mold. The gel coating becomes an integral part of the finished laminate and is normally used to improve the appearance of the surface. This procedure is described in more detail in Lubin, Handbook of Composites p. 764, Van Nostrand ReinholdCompany (1982), which is incorporated by reference to the present specification.

The article to be gel coated may be a polymer resin or a total or partially cured reinforcement composite in a polymeric resin matrix. The reinforcement material can be selected from any conventionally used in the composite plastics industry, such as glass fiber, polyethylene fiber, carbon fiber, metal fiber, ceramic fiber, etc., and the resin can be selected from a wide range of resins, such as polyester resins, epoxy resins, polyester carbonate resins, polycarbonate resins, polystyrene resins, polymethyl methacrylate resins, etc. The mold surface preferably corresponds to the shape of the negative embossed article. It can be an open mold or a matched mold.

The following examples are illustrative of the present invention.

Unless otherwise indicated, all percentages and quantity ratios are by weight.

E08785526 10-28-2011

Description of the test procedures.

Panel Preparation

Methyl ethyl ketone peroxide (MEKP) (1.8% by weight) is added to the gel coating and stirred for 1 minute. The coating is then sprayed onto a smooth, waxed and polished tempered glass plate with a thickness of 381-1016 microns (15-40 MILS being 1 MIL = 0.001 inches). After curing for 1-2 hours, at 3,175 mm (1/8 ") the laminate is performed using chopped fiberglass and a polyester resin (mat. 40% / 60% resin). The 1.2% by weight methyl ethyl ketone peroxide (MEKP) peroxide initiator is used to cure polyester resin. The laminate is allowed to cure for 16-20 hours, cetil is removed from the mold and cut into pieces of experimental parts.

Boiling Water Resistance

A part of 17.78 cm x 17.78 cm (7 "x 7") of the previous group is connected to a boiling water tank, with deionized water (ANSI Z124) and exposed for 100 h "flush" The exposed groups They are then calibrated on a scale of 0-5 for blisters, color change, change in the prominence of the fibers, cracks and loss of visible brightness with 0 = no change, and 5 = maximum change.

OUV weathering

The experimental groups are also subjected to the weathering test procedure (ASTM 53) using the 4 hour condensation cycle at 40 ° C, followed by exposure for 4 hours at 60 ° C to a UV lamp with a peak energy of 340 nm . Experimental groups are inspected at 500-hour intervals.

Rheology, Brookfield Viscometer

The thixotropy of the gel coating is determined by the use of a Brookfield viscometer. A 230 ml (8 oz) gel coating vessel at 25 ° C (77 ° F) is used as an experimental sample. With the use of a # 4 spindle in the viscometer the viscosity is measured at 2 and 20 rpm. The thixotropic index is calculated as the ratio of viscosity at 2 rpm to viscosity at 20 rpm.

Comparative Example 1: Preparation of a conventional unsaturated neopentyl glycol idesophthalic polyester resin

In a reactor equipped with a stirrer, a thermometer, a water separation column equipped with a reflux condenser and a nitrogen inlet, the following ingredients are added:

Components

Grams

Neopentyl glycol

1840

Propylene glycol

1042

Isophthalic acid

2270

Anhydride

1594

maleic

After the loaded mixture, it follows a two-stage procedure and a total of 539 parts is distilled. The reaction mixture is maintained at 220 ° C until an acid number of 15 to 20 is obtained. The reaction mixture is then cooled to less than 140 ° and the following ingredients are added:

Components

Grams

Methoxyhydroquinone

0.9

Styrene

2700

Comparative Example 2: Preparation of a conventional gel coating A gel coating is prepared by mixing the following ingredients:

Components

Grams

Resin solution of Comparative Example 1

48.0

12% cobalt dryer

0.2

Amorphous silica - smoked

1.3

50 E08785526 10-28-2011

(cont.)

Air release

0.45

Loads

21.6

Styrene

13.5

Methyl methacrylate

4.7

Sorbitan Monolaurate

0.25

Pigment paste

10.0

The resulting coating can then be cured by adding a 1.8% weight MEKP co-initiator and spraying the coating into a glass mold as described in the preparation of the experimental group.

Unless otherwise specified herein, the term " viscosity " refers to the viscosity of a polymer in 70% by weight styrene monomer NVM (nonvolatile material, see below) at 25 ° C, measured using a Brookfield viscometer.

In a preferred embodiment, the low VOC vinyl ester resin of this invention has a viscosity not greater than about 1,000 mPa.s (1000 cp), when the resin is dissolved in 30% styrene based on the total weight of resin and styrene.

The term "NVM" refers to non-volatile material dispersed in a volatile substance (eg, styrene monomer), measured in accordance with ASTM D1259.

The following examples (Examples 1-5) show the preparation of various acrylic polymers.

Example 1 (invention): Preparation of polyester acrylic resin

In a two-liter flask, equipped with a stirrer, thermometer, tube for introducing nitrogen and condenser, 427 grams of polycaprolactone triol (Tone ™ 0301 polyol, Dow Chemical) and 680 grams of hexahydrophthalic anhydride are placed. The temperature rises to 115 ° C and is maintained at that temperature for 3 hours. Then, 650 grams of glycidyl methacrylate, 0.2 grams of 2,3,5-trimethylhydroquinone and 0.8 grams of oxycyltriethylammonium chloride (TEBAC) are added, the reactor atmosphere is changed from nitrogen to nitrogen with 5% oxygen and The temperature rises to 115 ° C and is maintained at that temperature until the acid number is below 20. Then, 732 grams of styrene monomer and 0.2 grams of toluhydroquinone are added. The resulting depolyester acrylic resin has a viscosity of 350 mPa.s (350 cP) in a solution, containing 70% solids, in styrene.

Example 2 (invention): Preparation of polyester acrylic resin

1757 grams of polyester acrylic resin of Example 1 are prepared before the addition of styrene monomer. Then, 732 grams of 1,6-hexanediol dimethacrylate monomer (Sartomer SR239) and 0.2 grams of toluhydroquinone are added. The resulting polyester acrylic resin has a viscosity of 1950 mPa.s (1950 cP) in a solution, containing 70% solids, in acrylic monomer.

Example 3 (invention): Preparation of urethane modified polyester acrylic resin

In a two-liter flask, equipped with a stirrer, thermometer, tube for introducing nitrogen and condenser, 427 grams of polycaprolactone triol (Tone ™ 0301 polyol, Dow Chemical) and 680 grams of hexahydrophthalic anhydride are placed. The temperature rises to 115 ° C and is maintained at that temperature for 3 hours. Then, 650 grams of glycidyl methacrylate, 0.2 grams of 2,3,5-trimethylhydroquinone and 0.8 grams of oxycyltriethylammonium chloride (TEBAC) are added, the reactor atmosphere is changed from nitrogen to nitrogen with 5% oxygen and The temperature rises to 115 ° C and is maintained at that temperature until the acid number is below 20. Then, 102 grams of isophorone diisocyanate (IPDI, Bayer) are added and maintained at 90 ° C for 1 hour. Then 732 grams of styrene monomer and 0.2 grams of toluhydroquinone are added. The resulting depolyester acrylic resin has a viscosity of 880 mPa.s (880 cP) in a solution, containing 70% solids, in styrene.

Example 4 (invention): Preparation of polyester acrylic resin

In a two-liter flask, equipped with a stirrer, thermometer, tube for introducing nitrogen and a condenser, 92 grams of ethanolamine were added and 153 grams of propylene carbonate (Huntsman) was added dropwise at 20 ° C

- 35 ° C The reaction is maintained at 35 ° C for two hours after the period of addition time, then 663 grams of hexahydrophthalic anhydride are added. The temperature rises to 115 ° C and is maintained at that temperature for 3 hours. Then, 632 grams of glycidyl methacrylate, 0.2 grams of 2,3,5-trimethylhydroquinone and 0.8 grams of benzyltriethylammonium chloride (TEBAC) are added, the reactor atmosphere is changed from denitrogen to nitrogen with 5% oxygen and the temperature rises to 115 ° C and is maintained at that temperature until the acid number is less than 20. Then 652 grams of styrene monomer and 0.2 grams of hydrogenoluquinone are added. The resulting polyester acrylic resin has a viscosity of 250 mPa.s (250 cP) in a solution, with 70% solids content, in styrene.

E08785526 10-28-2011

Example 5 (invention): Preparation of polyester acrylic resin

In a two-liter flask, equipped with a stirrer, thermometer, a tube for introducing nitrogen and a condenser 354 grams of tris – 2-hydroxyethyl isocyanurate (THEIC), 233 grams of caprolactone and 0.2 grams of dibutyltin dilaurate. The temperature is raised to 160 ° C and maintained at that temperature for 3 hours.5 Then, 646 grams of hexahydrophthalic anhydride are added. The temperature is reduced to 115 ° C and maintained at that temperature for 3 hours. Then, 618 grams of glycidyl methacrylate, 0.2 grams of 2,3,5-trimethylhydroquinone and 0.8 grams of benzyltriethylammonium chloride (TEBAC) are added, the reactor atmosphere is changed from denitrogen to nitrogen with 5% oxygen and the temperature is maintained at 115 ° C and maintained at that temperature until the acid number is less than 20. Then 786 grams of styrene monomer and 0.2 are added.

10 grams of toluhydroquinone. The resulting polyester acrylic resin has a viscosity of 380 mPa.s (380 cP) in a solution, containing 70% solids, in styrene.

Example 6 (invention): Preparation of polyester acrylic resin

In a two-liter flask, equipped with a stirrer, thermometer, a tube for introducing nitrogen and a condenser secolocate 151 grams of fumaric acid, 601 grams of hexahydrophthalic anhydride, 174 grams of trimethylolpropane, 15 and 153 grams of 1,6-hexanediol. The temperature rises to 200 ° C and is maintained at this temperature for 4 hours. The temperature is reduced to 120 ° C, then 555 grams of glycidyl methacrylate, 0.2 grams of 2,3,5-trimethylhydroquinone and 0.8 grams of benzyltriethylammonium chloride (TEBAC) are added, the reactor atmosphere is changed from nitrogen to nitrogen with 5% oxygen and the temperature is maintained at 115 ° C and maintained at that temperature until the acid number is less than 20. Then 664 grams of monomer are added.

20 styrene and 0.2 grams of toluhydroquinone. The resulting polyester acrylic resin has a viscosity of 550 mPa.s (550 cP) in a solution, containing 70% solids, in styrene.

The viscosity and typical physical properties of the resins prepared in Examples 1 to 6 are listed in Table 1. All resins have 70% NVM for measuring viscosity and physical properties. Measurements of physical properties were made in the transparent casting of the polyester acrylic resin

25 resulting from each example.

Table 1 - Viscosity and physical properties of polyester acrylic resins

Resin Example

one 2 3 4 5 6

Viscosity (mPa.s or cP)

350 1950 880 250 380 550

Tensile strength (psi)

79 (11490) 58.6 (8500) 82.66 11990 92.17 13370 85.49 12400 86.0 (12480)

Elongation

4.71% 2.46% 5.10% 2.50% 4.39% 4.20%

Flexural Strength (psi)

137 (19870) 98.44 (14280) 145.5 (21110) 169.9 (23480) 142.8 (20710) 156.0 (22630)

HDT (ºC)

86 103 92 88 74 95.5

Example 7 (invention): Preparation of a polyester acrylic gel coating A gel coating is prepared by mixing the following ingredients:

Components

Grams

Resin solution of Comparative Example 1

69.27

Loads

10.0

Amorphous silica - smoked

1.8

Air release agent

0.45

12% cobalt dryer

0.18

Ethylene glycol

0.2

Styrene

8.1

Pigment paste

10.0

E08785526 10-28-2011

Comparison of QUV weathering between the gel coatings of Comparative Example 2 and Example 7 of the present invention.

Gel coating

Hours from dBrillo

Comparative example 2

500 2.00 –3.0

1000

3.86 –5.0

1500

7.00 –13.0

Example 7 of the invention

500 0.82 –6.0

1000

1.50 –7.0

Comparison of the boiling test between the gel coatings of Comparative Example 2 and Example 7 of the present invention.

Comparative example 2

Example 7

Blisters

1.58 2.00

Color change

1.83 0.67

Fiber prominence

0.50 0.67

Cracks

0.00 0.00

Loss of brightness

0.33 0.33

Total

4.24 3.67

Rheology, Brookfield Viscometer

The viscosity measurements obtained using a Brookfield viscometer of a gel coating similar to 10 Comparative Example 2 are as follows:

RPM viscosity (mPa.s or cP)

Comparative example 2 Example 7

2

20300 19500

4

12500 10850

twenty

3500 3260

Thixotropic index

5.8 6.0

The new acrylic resin has a VOC of around 30%, which complies with the new MACT regulations for styrene emissions for the marine industry. The resin of Example 2 also shows that it is possible to obtain a zero VOC resin with a viscosity of less than 2000 mPa.s (2000 cP) with 30% HDMA monomer.

E08785526 10-28-2011

Claims (18)

one.

A crosslinkable resin composition, comprising a polyester acrylic polymer having two or more polymerizable carbon-carbon double bonds, which are acrylate groups, in each molecule and at least one polymerizable vinyl monomer, said polyester acrylic polymer being a product of reaction of a polyacid and an unsaturated epoxide, with a number average molecular weight of 560-200 and a viscosity of less than 1500 mPa.s (1500 cP) in a solution with 30% styrene monomer, said polyester acrylic polymer containing less than 10% by weight of the aromatic ring structure, said polyacid being an ester medium and the reaction product of a polyol or a mixture of polyols with one or more polycarboxylic acids or acid anhydrides, said polyol or mixture of polyols having an average of at least two hydroxyl groups in the molecule, with an average hydroxyl number of 56 to 1830, and with an average molecular weight edio in number between 72 and 2000.

2.

A resin composition according to claim 1, wherein said unsaturated epoxides as defined in accordance with claim 1 include at least one glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether.

3.

A resin composition according to claims 1 or 2, wherein said polyol as defined according to claim 1 has a hydroxyl number of 130 to 1500, and a number average molecular weight between 110 and 1800.

Four.

A resin composition according to any one of claims 1 to 3, wherein said polyols as defined according to claims 1 or 3, are simple polyols containing from 2 to 20 carbon atoms, or polymer polyols of polyols. of polyester which include polycaprolactone polyols, polyurethane polyols, polyether polyols, polycarbonate or polyester carbonate polyols, acrylic polyols.

5.

A resin composition according to any one of claims 1 to 4, wherein said polycarboxylic acids or anhydrides as defined according to claim 1 contain from 2 to 20 carbon atoms.

6.

A resin composition according to claim 5, wherein said polycarboxylic acids and anhydrides are selected from aliphatic, cycloaliphatic, olefinic and cycloolefinic acids and / or anhydrides.

7.

A resin composition according to any one of claims 1 to 6, wherein polyester acrylic dichopolymer has free secondary OH groups and unsaturated acrylate ester bonds.

8.

A resin composition according to any one of claims 1 to 7, wherein said free secondary OH groups are further reacted with at least one diisocyanate, polyisocyanate or isocyanate functional prepolymer or a polycarboxylic acid anhydride.

9.

A resin composition according to any one of claims 1 to 8, wherein polymerizable vinyl dichomonomer as defined in accordance with claim 1 includes aromatic monomeric compounds selected from styrene, alpha-methylstyrene, dichlorostyrene, vinyl naphthalene, vinyl phenol and the like, unsaturated esters, selected from acrylic and methacrylic esters, vinyl laurate, and the like, unsaturated acids, selected from acrylic and alpha-alkylacrylic acids, butenoic acid, allylbenzoic acid, vinylbenzoic acid, and the like, halides, selected from vinyl chloride, vinylidene chloride, nitriles, selected from deacrylonitrile, methacrylonitrile, diolefins, selected from butadiene, isoprene, methylpentadiene, esters of polycarboxylic acids, selected from diallyl phthalate, divinyl succinate, diallyl maleate, dicylorohalate, tetrahydrolate, tetrahydrolate, tetrahydrolate, similar , and mixtures of the same.

10.

A thermosetting resin blend composition, which contains a resin composition as a sedefine according to any one of claims 1 to 9 and at least one other thermosetting resin.

eleven.

A resin composition according to any one of claims 1 to 9 or a thermosetting resin blend composition as defined according to claim 10, wherein they are suitable for gel coatings.

12.

A process for preparing a resin composition as defined according to any one of claims 1 to 9, comprising:

to.

 Preparation of a polyacid by reacting a polyol with a polycarboxylic acid and / or acid anhydride with said polyol having an average of at least two hydroxyl groups in the molecule and a hydroxyl number of 56 to 1830 and an average molecular weight of 72 to 2,000 , said carboxylic acid anhydride having at least one group of intramolecular carboxylic anhydride.

b.

 Esterification of the resulting polyacid with an unsaturated epoxide.

13.

A gel coating or molding composition, comprising at least one resin composition as defined according to any one of claims 1 to 9, or a resin mixture composition as defined according to claim 10.

14.

A gel coating composition according to claim 13, which is a pigmented gel coating composition that in addition to the resin composition additionally contains at least one pigment.

fifteen.

Use of a resin composition as defined according to any one of claims 1 to 9 or of a thermosetting resin blend composition as defined according to claim 10,

E08785526 10-28-2011 for the manufacture of pigmented or non-pigmented gel coatings or mold coatings, preferably for maritime, sanitary or automotive applications, or for the manufacture of molded composite materials, preferably for reinforced composite products. 16. Use according to claim 15, which is for gel coatings and said gel coatings are 5 for coating a molded composite substrate that is made from a resin composition according to any one of claims 1 to 9 or a thermosetting resin blend composition as defined, according to claim 10 or from of unsaturated polyester resins from (UPR) or from vinyl ester or any other thermosetting resin. 17. A gel coating or molded composite material, resulting from a gel coating or a Composite molding material as defined according to claims 13 or 14 or the use according to claims 15 or 16. 18. An article comprising the gel coating or molded composite as defined in accordance with claim 17.